1. Field of the Invention
The present invention relates to a method for manufacturing a printed circuit board.
2. Description of the Background Art
Conventional methods for manufacturing a printed circuit board comprise opening holes in a copper plate, filling epoxy resins in the holes, additionally forming circuit layers on both the faces of two first resin plates, further forming circuit layers on one face of the two second resin plates and simultaneously attaching copper foils on the other face thereof, bonding the first resin plates on both the faces of the copper plate by means of prepreg, further bonding the second resin plates on both the faces thereof by means of prepreg, opening through the copper plate, the first resin plates and the second resin plates through-hole openings with the center line approximately lying on the center line of the holes, forming a copper-plated layer by electroless copper plating and subsequent electrolytic copper plating, and selectively etching the copper-plated layer and the copper foils, thereby providing through holes.
According to such methods for manufacturing a printed circuit board, an interface is present between the first and second resin plates as the insulating layers and the prepreg, and therefore, the resulting printed circuit board may eventually be warped.